Control for clamps



Aug. 31, 1943. D. H. cRAvENER, JR

CONTROL FOR CLAMPS Filed Dec. 1, 1941 2 Sheets-Sheet 1 Aug. 31, 1943. D.CRAVENER, JR 2,328,262

CONTROL FOR CLAMPS Filed Dec. 1, 1941 2 sheets-sheet 2 l t 2,328,262 owhen the blank is stationary, whereby to permit 5.` A clamping device asdescribed in. claim 3; a

rotatablek platform adapted lto support the form and impart rotationthereto, and means for rais- .o raised.

ing the form from the platform to arrest therol tation of the form, saidextemaloperating means for the weights` being responsive to the raisingmovement of the form such that the ex- `ternalmeans is operative whenthe form is no longer driven.

o 6. A clamping device for holding a blankI on a rotatable form; saiddevice comprising a weight,

`means`for pivotally supporting the weight from the form, said pivotalsupport being located eccentrlcally with respect to the `center ofgravityof the weight, a finger extending from the weight and adaptednormally to extend over the blank and prevent it from leaving the formwhen the weight is not rotated, an extension on the Weight, and externalmeans adapted to engage the extension to rotate `the weight and itsassociated fmger away from the form, thereby to permit the `rernovalofthe blank from the form.

7. `A clamping device for holding a blank on a rotatableform, said formbeing rotatable in a horizontal plane and having a conical surfacethereon for supporting a blank, said device comprising a plurality ofweights, pairs of apertured lugs extending from the periphery of theform and t equidistantly spaced thereabout, pins passing through theapertures in the lugs and through the weights to provide a pivotalsupport for the weights, the centerofgravity of the weights being belowthe pins;` a finger extending radially inwardly from each of thefwelghtsover the conical o portion of the form, said iingersnormally being linclined over a blank when the form` is at rest,

a `lateral extension on each weight, and means l operating on theextensions torotate the weights t and their associated fingers in amanner to `re- `move the nngers `from the blank, thereby p ermitting theblank to be withdrawn from the form. l o n 8.1A` clamping device`asdescribed in claim 7, a rotatable platform adapted to support the formand impart rotationpthereto, and means for rais-V ing the form from theplatform to arrest the rotation of the form, said means operating ontheextensions on thel weights comprising a `:lxed i abutment overlying theextensions and adaptedy to` contact the extensions While the form isVbeing 9. A clamping device for` holding a blank on a rotatable form,saiddevice comprising a plurali. ityof weightameans for movably mountingsaid V weights on the form, said mounting means being adapted to permitthe weights to moveunder the influence of centrifugal force, andmechanical clamping elements'movable with the weights and adapted in oneposition `to clamp the blank to the form, in another position to preventthe blank from leaving the form, and in a third position to support theblank over the form.

10. A clamping device forholding a blank on arotatable form, said devicecomprising a plurality of weights, means for pivotally mounting saidweights on the form, said pivotal mounting being eccentric to the centerof gravity of the weights and being adapted to `permit the Weights torotate under the influence of centrifugal force, means operated by theweights and adapted `to clamp the blank to the form,` said form havingslots therein which are covered by the blank, and

4means likewise operated by the Weights and4 adapted to pass through theslots to push the blank off the form when the form is not rotating. 11.A clamping device for holding a blank on a rotatable-form, said devicecomprising a plurality i of weights, means for mounting' said weights onthe form for relative movementtherewith, said mounting means beingadapted to permit the weights to move under the inuence of `centrifugalforce, and mechanical clamping elements operated by the weights andadapted in one position of the Weights toclamp` the blank, to they" formand in another blank over the form.

DONALD H. cRAvENERon.

position to support the

